xix Acknowledgment I would like to thank the following institutions for financially contributing towards the writing of this book: Harvard University through the Harvard/SA Fellowship, Wolfson College (University of Cambridge) for a Visiting Fellowship that I was granted for a year and the University of the Witwatersrand. I also would like to thank my following people: Dr Vincent Fulufhelo Nelwamondo, Busisiwe Vilakazi, Shakir Mohamed, Dalton Lunga and Mussa Abdella for their assistance in developing this manuscript. Furthermore, I thank the following former students for assisting me in running the simulations: George Sssali, Vukosi Marivate, A.K. Mohamed, Jaisheel Mistry, Dr. Brain Leke and Dan Golding. In particular, I thank Dr Ian Kennedy and Lesedi Masisi. I dedicate this book to the schools that gave me the foundation to always seek excellence in every- thing I do and these are: Mbilwi Secondary School, Case Western Reserve University, University of Pretoria, University of Cambridge (St. John' College) and Imperial College (London). I also thank my